RESUMO
objective: To evaluate the effects of the pendulum appliance on arch length, arch width, overbite and overjet. Methods: Pendulum appliances were applied for distalization of maxillary molars in 37 patients whith class Ⅱ malocclusion and 1-Ⅱ degree crowded dentition in upper dental arch. Pretreatment and posttreatment model analysis was conducted. Results: 37 patients treated for 18.2?4.5 weeks with pendulum appliance were accomplished . The increase of arch arc length between the maxillary first molars was (17.36?4.38) mm, the decrease of anterior arch width (-3.04?1.59) mm, and the decrease of posterior arch width (-1.29?2.01) mm . Differences between the pretreatment and posttreatment were significant, including arch arc length between the maxillary first molars ( P